Hello
I test intel image open denoise and it look better than the denoiser of Maxwell and of course very very fast
denoiser of maxwell don't work i don't know why and it is very slow
here the full steps and the result:
1-Download intel image open denoise : https://openimagedenoise.github.io/downloads.html and extract the folder
2-Render : the full image with two channels : Normal and Reflectance
3-Save every image as EXR32
4-Open the images with Photoshop and save them as PFM
5-create text file with this lines: .\denoise -hdr c.pfm -alb a.pfm -nrm n.pfm -o output.pfm and change the extension to cmd (for example : run.cmd)In my case i save the render as : c.pfm , normal as n.pfm, reflectance as a.pfm
--------------------The result: the Render SL = 5:

well it works, thanks! I gonna test it with some more renders before verdict... but if it works as good as it looks on first attempts, we need to write a script to automate the process, or some simple gui that asks for the 3 files and runs the denoise process.